The division bench of Chief Justice Bhaskar Bhattacharya and Justice JB Pardiwala said the section is in breach of fundamental rights guaranteed under Articles 14 (right to equality) and 21 (right to life and liberty) of the Constitution, so it was invalid.

The constitutional validity of Sec 66 (1)(b) had been challenged by Balaji Wafers Company, on the ground that the section discriminated on the basis of gender.

Mahila Utkarsh Trust, an NGO based in Amreli district's Damnagar town, had also challenged the provision as some of the women in the area were denied employment by ginning factories citing the Factory Act. The court had clubbed the two petitions.

The Madras High Court has earlier ruled Section 66 (1)(b) as constitutionally invalid while the Kerala High Court ruled that it was a valid provision.

The court quoted both these judgements as well as the Supreme Court ruling that said that women can be employed even at a place in night shifts where alcoholic beverages are served.

The court observed that women now work even at the grassroot level, as in police or other government duties.

"The section does not allow even a female entrepreneur who owns the factory to supervise her own staff during the night shift because the Act does not provide for it. In that case, she will be forced to employ a male supervisor for the night shift or she will have to shut down the night shifts in the factory," the court said.